Hydrochloric acid, also referred to as hydrogen chloride, is used and processed in the chemical industry in many different ways. Typical fields of application are chloralkali electrolysis or the production of vinyl chloride. Hydrochloric acid is often obtained as a by-product, for example in the chlorination of organic compounds. However, the demand for hydrochloric acid cannot be met in this way.
Special corrosion-resistant hydrogen chloride synthesis facilities are therefore used in the industry for synthetic production. In these facilities, chlorine gas and hydrogen gas react at temperatures of up to 2500° C. so as to form hydrogen chloride gas. The combustion reaction occurs in the combustion chamber. The burner, through which the feed gases flow into the combustion chamber, consists of two concentric tubes, chlorine gas being supplied via the inner tube and hydrogen gas via the outer tube. The combustion reaction occurs in the flame above the burner. In order to achieve as high a conversion of chlorine as possible, an excess of hydrogen of from 5 to 15% is usually set. The reaction is completed at the outlet of the combustion chamber and the hydrogen chloride gas formed flows through the absorption part of the synthesis means, where it is absorbed to form hydrochloric acid (U.S. Pat. No. 9,415,364).
One problem in the production of hydrogen chloride is that of incomplete combustion which leads to a higher proportion of free chlorine in the product acid. As a result of the reactant gases being insufficiently mixed, the geometry of the flame is very long and narrow, which in turn requires a large combustion chamber. This has a negative impact on the level of costs.